Manufacture of improved hydrocarbon products



Oct. 29, 1935.

MANUFACTURE OF IMPROVED HYDROCARBON ,PRODUGTS E. 'AYRES ET AL FiledMarch. 10, 1932 CIRCULATJNG 5R8 PUMP AGITATOR 51. up 615 @zcsl vER FIREAND STEAM STILL FILTER PRESS FOR RES/DUE E ene 07 ms Hamel GSZvith,

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Patented Oct 29, 1935 UNITED STATES PATENT OFFICE MANUFACTURE OFIMPROVED HYDRO- CARBON PRODUCTS Application March 10, 1932, Serial No.598,096 6 Claims. (01. 196-78) This invention relates to manufacture oflubricating oils; and it comprises a process of produc ing finished highquality lubricating oils from mixtures of technical petroleum stocksranging in type from tar residues to light distillates, wherein arelatively high boiling petroleum stock is mixed with a lower boilingstock, the mixture is heated to a temperature not above 300 F. in thepresence of anhydrous aluminum chlorid and added HCl to produce asynthetic stock of characteristics intermediate those of the twooriginal stocks and in yield much greater than is obtainable by asimilar treatment applied to the original stocks separately, thesynthetic stock which contains some aluminum chlorid sludge is settledfor removal of the bulk of sludge, is decanted, traces of aluminumchlorid sludge remaining in suspension in the decanted liquid aredecomposed and the products of decomposition are substantiallycompletely removed, to pro duce a finished lubricating oil substantiallyfree from impurities; all as more fully hereinafter set forth and asclaimed.

Several different, specific eifects of anhydrous aluminum chloride onpetroleum stocks have been described in the literature. A few of theseeffects now form the basis of commercial processes. For example, it isknown that aluminum chlorid has the effect of causing the condensationor polymerization of hydrocarbons at relatively moderate temperatures.-Bythis means, synthetic lubricating oils of naphthenic'type have beenmade from volatile olefines. The refining of lubricating oil stocks bywarming with aluminum chloride is also known. Such processing involvesthe removal in the form of a heavy sludge of certain undesirableconstituents of the stock, possibly by the condensation of theconstituents least saturated with respect tomhydrggen to form highmolecular weight compounds insoluble in oil. It is characteristic ofsuch processes that the oil is changed in character; they break down themolecular structure of the oil and produce the formation of substantialproportions ofoils of lower viscosity than that of the startingmaterial. The reason .for this breaking down effect is that the aluminumchloride of itself is not ordinarily an effective refining agent unlessthe temperature of the oil is above normal. In any event a considerableamount of the starting stock is lost to the sludge and the yield ofrefined oil is low.

A third example of the known eifects of aluminum chloride is the use ofthis material to promote the breaking down of heavier oils to form motorfuel and kerosene. At temperatures above 300 F. the analytic orconverting effect of aluminum chloride predominates, and at temperaturesbelow-300 F. the synthetic effect of aluminum chloride, althoughdominating the analytic e1.-v

fect, may cause the formation of oil insoluble bodies in large amounts.

In the present invention in its aspect of producing a syntheticlubricating oil stock in high yield, aluminum chlorid in the presence ofadded HCl is used for synthesizing lubricating oils from mixtures ofhydrocarbon stocks. In the principal embodiment of the invention, arelatively thick,

viscous and high boiling oil stock is admixed with a lighter stock. Inthe course of treatment, some 10 sort of combination of the stocks takesplace. There is, to a certain extent, what may be called an averaging ofthe two oils; and the new oil produced therefrom may be termed asynthetic product. That this synthesizing effect occurs is evidenced bythe fact that the yield of oil obtained in the process is much greaterthan the sum of the yields obtained by carrying out a similar processupon the two components separately and mixing the products. I

The HCl as used in our process appears to have a transitory function.The entire chlorine content of the gas appears at the end of thereaction as hydrogen chloride. No chlorinated hydrocarbons appear in theproduct. The hydrogen chloride can be readily recovered at the end ofthe reaction and can then be reintroduced or recycled. t I

Our synthesizing process is carried out upon mixtures of hydrocarbons ofdifferent characteristics. In the principal embodiment of the invention,the two hydrocarbon components are a high boiling petroleum stock andalower boiling stock. To the extent that the two stocks combinemolecularly, the yield of high grade products is higher than the yieldobtainable froma treatment of the charging stocks separately. When oneof the hydrocarbon components is of low molecular weight, its presencehas an .additional effect: a thinning action; ensuring, by dilution ofviscous oils, better contact with the aluminum chlorid.

In general, our process is accomplished by contacting dry hydrogenchloride, for example, with the hydrocarbon stock to be treated, addinga suitable proportion of anhydrous aluminum chloride, agitating at asuitable temperature for a suitable period of time, separating thesludge from the residual'oil, neutralizing the separated oil andfinishing in such manner as to obtain the desired appearance or purityof product.

The contacting of the oil with dry gaseous hydrogen chloride in ourprocess can be accomplished conveniently at ordinary temperatures andpressures, but elevated pressures may be advantageous particularly whenelevated temperatures are employed. Pressures up to pounds per squareinch have been used in some cases. The oil may be merely held in contactwith an atmosphere of the hydrogen chloride, 6

with or without agitation, or the latter may be blown-through a body ofthe oil. When atmospheric pressure is used it is advantageous tomaintain the contact with hydrogen chloride for an hour or more. Atslightly elevated temperatures and under super-atmospheric pressures thesame degree of preparation of the hydrocarbon stock may be accomplishedwithin 5 to 10 minutes. It is advantageous, although not necessary tomaintain contact with excess hydrogen chloride during the subsequenttreatment with aluminum chloride. Aluminum chloride in its reaction withhydrocarbons generates some hydrogen chloride but we have found that thesmall amount of hydrogen chloride so generated is not capable of givingthe results obtainable by thisinvention.

An excess over this amount is necessary. It has also been found that thealuminum chloride used in our process cannot be replaced by metallicaluminum used with C12 or HG]. If there is a reaction between suchaluminum and the dry hydrogen chloride or chlorine used in our process,this reaction is, at all events, not sufflciently rapid. The results arenot the same.

Instead of contacting the hydrocarbon stock with hydrogen chloride priorto treatment with aluminum chloride, satisfactory results may be securedby contacting with hydrogen chloride only during the treatment withaluminum chloride, provided this treatment is conducted at moderatetemperatures.

We have found it practical in some instances to substitute gaseouschlorin for the 1101 gas used in our process prior to or duringtreatment of stock with aluminum chloride. So doing, the net resultappears to be the same; the chlorine is quantitatively removed at theend of the reaction as I-ICl.

' Operation is under conditions such that no substantial chlorination ofthe hydrocarbons present takes place.

The proportion of anhydrous aluminum chloride used in our process may bevaried within wide limits. We advantageously use between 1 and 10 percent by weight of the hydrocarbon stock. In the processes illustratedsubsequently 1 per cent of aluminum chloride was found sufficient togive a 94 per cent yield of a slightly improved lubricating oil with aviscosity at 210 F. of 86 seconds compared with 75 for the startingmaterial, which in this case was a lubricating stock from a Coastalcrude. But with the use 01' 10 per cent aluminum chloride and the samelubricating stock, the viscosity at 210 F. of the finished product wasraised to 107 seconds and the quality approached that of Pennsylvaniaoil, with an 8'7 per cent yield. Larger proportions of aluminum chlorideare usually attended by larger losses. The efiects on the reduction ofcarbon residue are more marked at higher temperatures with largerproportions of aluminum chloride, but at lower temperatures relativelylittle aluminum chloride is required. With 3 per cent aluminum chlorideat room temperature the carbon residue of a mid-continent bright stockwith a viscosity at 210 F. of 150 seconds can be reduced from 1.75 to0.55, for example.

By the use of an excess of hydrogen chloride muchless aluminum chlorideis required than in the ordinary known process. The temperaturessuitable for our processes vary between those considerably below roomtemperature and those somewhat above 212 F. Temperatures above 300 F.are not satisfactory because at elevated temperatures the action ofaluminum chloride is to break down the hydrocarbons to form light gencarbon ratio hydrocarbon stocks, the maximum effect on theviscosity-temperature relationship appears to be at low temperatures,whereas with relatively high hydrogen carbon ratio hydrocarbon stocks,higher temperatures produce better results.

The time of agitation of the hydrocarbon stock with aluminum chlorideshould be long enough to insure a complete reaction. At low temperaturesit is obviously advantageous to use a longer time than at hightemperatures. In general a period of one hour gives satisfactoryresults.

The dilution of the hydrocarbon stock with low molecular weighthydrocarbons is advantageous in the case of the treatment ofhydrocarbons of higher molecular weight and particularly of viscousoils. For example, in the treatment of pressure-still tar alone there isobtained a 33 per cent yield of good quality oil with a viscosity of 42seconds at 210 F., whereas in the presence of an equal part of a crackedgasoline a 9'7 per cent yield may be obtained of oil of the same qualityand viscosity. On the other hand after a treatment of the crackedgasoline sepa-- rately, conditions of treatment being otherwise thesame, no measurable yield of lubricating oil was secured. The treatmentof a mid-continent bright stock alone gives a 60 per cent yield of oilof Pennsylvania quality with viscosity of seconds at 210 F., but in thepresence of 20 per cent uncracked mid-continent gasoline we obtain a 65per cent yield of oil of Pennsylvania quality with viscosity of 143seconds (S. U. V.).

The chemical characteristics of the diluent have a marked cifect on theresults, but all types are useful. Pure olefines such as amylenes may beused to advantage. Cracked gasolines containing ring compounds as wellas olefines and uncracked gasolines' containing principally paraflinsand naphthenes, or even pure benzene or toluene, or any combinations ofthese hydrocarbons, may be used. The increase in yield is somewhat moremarked with diluents of the olefine type. This is not because of apolymerization or condensation of the olefins to form an oil, by theaction of aluminum chloride, because a treatment of the olefine aloneunder the prescribed conditions gives no measurable yield of lubricatingoil.

In the case of the treatment of certain types of stocks by our process,particularly those types that contain unsaturated lubricating fractionsor naphthene lubricating fractions, we often secure lubricating ,oilsthat are mixtures of oils of improved quality with some fractions ofinferior quality. The formation of refined lubricating oil fractions ofpoorer quality appears to be the result of side reactions, withpolymerization or condensation of heavy hydrocarbons to products havingthe undesirable characteristics of low gravities, poorviscosity-temperature curves, and comparatively high carbon residuetests. These side reactions or by-products occasionally encountered areevidently largely due to the-presence of substances in thechargingstocks of the nature of hydrocarbons of the di-olefine, acetylenic oraromatic types. When such reaction products are encountered insuflicient amount to affect the quality of the finished lubricatingoilmixture to an undesirable extent, we can often effect someimprovement in quality by distilling from the final treated oil,fractions of improved quality, as the undesirable products are often ofmuch higher boiling range than the other fractions and therefore .can beconcentrated in a heavy residual oil from a fire and steam reduction ateither atmospheric pressure or under vacuum.

The intermediate stock obtained by the treatment described of a mixtureof charging stocks with the aid of aluminum chlorid and added HCl, isnot a finished lubricating oil and cannot be used directly as such. Itis necessary to apply a finishing treatment to get out all traces ofaluminum chlorid, or aluminum chlorid sludge, remaining in thesynthesized stock. The stocks do not yield readily to treatment bycommon methods for finishing oils in general and we have developedmethods particularly suitable for finishing such stocks. Three finishingmethods which we have found most suitable, for producing a finished oilfrom syntheticstocks are the following:

1. To the sour oil decanted from the aluminum chloride sludge is addedsome fine clay and hydrated lime; the. oil thereafter being filtered.Heating of the oil-lime-clay mixture before filtering is usuallyadvantageous. Two-tenths of a pound of lime per barrel of oil per acidnumber is about suficient for neutralization, but it is desirable to usean excess such as 0.6 pound per barrel per acid number. Suflicient clayshould be used to facilitate filtration. This usually requires from 0.4to 0.8 pound of clay per gallon of oil, when natural Florida or Georgiaclay is employed.

2. The sour oil decanted from the aluminum chloride sludge isagitatedwith dilute sulfuric acid to decompose suspended aluminumchloride sludge or compounds. After settling out the dilute acid wash,the oil may be treated, if desired, with a small amount of strongsulfuric acid, or contacted with fine clay, or filtered through coarseburned'clay. The dilute acid may be as weak as 5 per cent or less, ormay be stronger than 20 per cent unless, in a particular case, thestrong acid causes a stable suspension in the oil of acid sludgeparticles or decomposition products therefrom.

3. The sour oil decanted from the aluminum chloride sludge is heated toa temperature at which thetracesof suspended aluminum chloride sludge.will completely react with the oil. This temperature is usually between450 F. and 550 F. After the sludge is spent, the oil can besatisfactorily filtered.

Our invention is illustrated in the accompanying drawing which shows, inthe form of flow sheets (Figs. 1 and2) two typical processes within thepurview of our invention, wherein a lubricating oil stock is mixed witha lighter hydrocarbon and the mixture is treated by a. series ofsuccessive operations with the ultimate production of a finishedlubricating oil of improved properties. The several successiveoperations are indicated on the flow sheets by appropriate legends.

Referring to the flow sheet of Fig. 1, a lubricating oil stock is shownintroduced into an agitator together with a light fraction. Aluminumchloride is introduced and hydrogen chloride is circulated through theagitator. Sludge is drawn ofi after completion of the reaction and therefrom the still while the bottoms are passed through a filter press forremoval of clay and lime residues, a finished lubricating oil beingfinally recovered.

Fig. 2 shows a modification of the invention, the finishing steps beingdifferent. The treatment with aluminum chloride and HCl is the same asin Fig. 1. The sour oil obtained at the end of this treatment is settledand is then mixed with a suitable quantity of dilute sulfuric acid withagitation. The oil is then permitted to settle out impurities, and iscontacted with fine clay or illtered through coarse burned clay. Afinished lubricating oil of high quality is recovered by this treatment.

Our invention is further illustrated by the following illustrativeexamples which represent practical embodiments thereof.

1. Treatment of 'mid-continent bright stock One hundred volumes of abright stock from Oklahoma crude petroleum were contacted with dryhydrogen chloride at ordinary temperature and pressure for four hours.While continuing the contact of hydrogen chloride, the oil was thenwarmed to 275 F. and stirred for about 2 hours with 10 per cent byweight of anhydrous aluminum chloride. The sludge was permitted tosettle and the decanted sour oil was steamed at 450 F. with 0.5 poundfine clay per gallon and 0.6 pound hydrated lime per acid number perbarrel. The residue was filtered through-paper. The yield of finishedoil was found tobe 60 volumes. The following table shows comparativetests made on the charging stock and on the final products.

Charging stock Product Gravity: A. P. I 22.8 29,9 Viscosity, S. U. V.:

100 F 3,007 846 56 105 420 505 +25 Color, N. P. A 4. 75 l. 75 Carbonresidue: Per cent 1.42 0.04

The above tests show a greater effect on the viscosity index than isnormally secured.

2. Treatment of mid-continent bright stock example. The yield offinished oil was 149 vol- .umes. Comparative tests on this oil yieldedthe followm g results:

x 1 Product 7 Gravity: A. P. I 23.0 24. Viscosity, S. U. V. 3

210 151 119 Viscosity, index (Dean and Davis 73 78 Flash, 0. 0.: F. 545495 Fire, 0. 0.: F 630 570 Pour: F +15 +15 Color, N. P. A 7.5 7. 5Carbon residue: Per cent- 1.75 0. 55

This example illustrates a remarkably high yield of oil of reducedcarbon residue.

3. Treatment of lubricating distillate from Coastal crude On hundredvolumes of lubricating distillate from Coastal .crude petroleum weremixed with twenty-eight voliunes of amylene. This mixture was contacted,with dry hydrogen chloride at room temperature while stirring with 10per cent by weight of anhydrous aluminum chloride for a.

period of 4 hours. The sludge was permitted to settle and the sour oilwas then treated as outlined in the first example. The yield of finishedoil was found to be 86.6 volumes having the following comparative tests:

This example shows a great increase in viscosity index attended by anincrease in viscosity at 210 F.

4. Treatment of reduced pressure-still tar D One hundred volumes ofreduced pressure-still tar of 17.3 A. P. I. gravity and viscosity, S. U.V., of seconds at 100 F., were mixed with 28.7 volumes of uncrackedgasoline. This mixture was contacted with dry hydrogen chloride for onehour at 175 F. under 100 pounds pressure. The oil was then stirred atroom temperature with 10 per cent by weight 01. anhydrous aluminumchloride for 4 hours at atmospheric pressure while maintaining thepresence of an excess of dry hydrogen chloride. The sludge was permittedto settle and the sour oil was then treated as in the first example. Theyield of finished This example shows a good yield of oil of fair qualityfrom a tar.

5. Treatment of reduced pressure-still tar lubricating One hundredvolumes of reduced pressure-still tar of 16.4 A. P. I. gravity andviscosity, S. U. V., of seconds at 100 F., were mixed with an equalvolume of cracked gasoline of 77.4 A. P. I. gravity. This mixture wascontacted with dry hydrogen chloride for 4 hours at ordinary temperature and pressure. The oil was then stirred at 40 F. with 10 percent by weight of anhydrous aluminum chloride for ten hours atatmospheric pressure. The sludge was permitted to settle and the souroil was treated as in the first example.

This example shows the improved yields obtainable by the use of crackedinstead of uncracked gasoline.

6. Treatment of light gas oil to yield kerosene One hundred volumes oflight cracked gas oil from Venezuela crude petroleum were mixed with 20volumes of amylene and stirred at room temperature with 10 per cent byweight of anhydrous aluminum chloride for 8 hours at atmosphericpressure. An atmosphere of dry hydrogen chloridewas maintained over themixture during stirring. The sludge was permitted to settle and the souroil was then distilled with 0.1 per cent by weight of hydrated lime. Theyield of finished kerosene was found to be 7 5 volumes having thefollowing comparative tests:

augi Kerosene Gravity: A. P. I 36.5 46.0 Color, Saybo1t. +25 Viscosity,Saybolt thermo-viscosimeter: 400 Flash, '1. C. 0.: F 139 Sulfur (L): Percent 0. 36 0. 003 Acid heat: "F l Distillation, assay:

Over point: F 374 352 End point: T... 588 550 Percent at 392 F l0 11 50088 92 590 97 50 percent at: F. 428 435 This example shows an increasedyield of high grade kerosene by mutual reaction with amylene duringrefining.

The above examples illustrate a few of the ways in which our inventionmay be used to improve technical petroleum products. The operatingconditions under which the process is carried out can be widely variedwithout departing from the spirit of our invention. In many cases theprocedure may be varied to suit the particular material which is beingtreated or the particular product which it is desired to produce. Someof these variations have been outlined in the preceding discussion.Others will be immediately evident to those skilled inthe art.

Reference is made to our copending application, Serial No. 628,446,filed March 18, 1933, which discloses treatment of oil stocks with ahalogenated hydrocarbon in the presence of aluminum chlorid.

What we ,claim is:

1. The process of obtaining an improved lubricating oil in high yieldwhich comprises treating a mixture of a-relatively high boilingpetroleum stock and a lower boiling petroleum stock.

at a temperature not above about 300 F. with aluminum chlorid in thepresence of added HCl to produce a synthetic lubricating oil stock ofcharacteristics intermediate those of the two original stocks and inyield substantially greater than is obtainable by a similar separatetreatment of the two original stocks, settling out the bulk of aluminumchlorid sludge tormed, de canting, decomposing the traces of aluminumchlorid sludge'that remain in suspension in the decanted liquid byagitating the oil with dilute sulfuric acid, separating the acid,contacting with clay and filtering.

2. The process of claim 1 wherein sulfuric acid of -5 to per centstrength is employed.

3. The process of obtaining an improved lubricating oil free fromimpurities and in high yield which comprises mixing a relatively highmolecular weight petroleum stock with a lower molecular weight petroleumstock, treating the mixture with aluminum chlorid in the presence ofadded HCl at a temperature not above about 300 F. to produce a syntheticlubricating oil stock of characteristics intermediate those of the twooriginal stocks and in yield substantially greater than that obtainableby a similar separate treatment of the two original stocks, settling outthe bulk of aluminum chlorid sludge remaining in the stock, decanting,decomposing traces of aluminum chlorid sludge remaining in the decantedliquid by heating with a small amount of clay to a temperature in thegeneral neighborhood of 450 F. in the presence of a small amount of.clay and about 0.6 pounds of lime per acid number per barrel andremoving the products of decomposition by filtering to secure a refinedlubricating oil of the character described. I

4. In the production of improved lubricating oils by treatment oradmixed unrefined stocks of difierent hydrocarbons in the presence ofalu- 5 minum chlorid to give a synthetic product containing suspendedaluminum chlorid sludge, the process of finishing which comprisessettling the product of the aluminum chlorid treatment to remove thebulk of the aluminum chlorid sludge 10 therein, decanting, decomposingthe remaining aluminum chlorid sludge with dilute sulfuric acid,separating the acid, contacting with clay and filtering.

5. The process of claim 4 wherein the acid 5 strength is about 5 to 20per cent.

6. In the process of obtaining a refined pure lubricating oil frommixtures of unrefined stocks with the aid of aluminum chlorid thefinishing procedure which comprises settling out from the 20 aluminumchlorid treatment product the bulk of aluminum chlorid sludge,decanting, decomposing traces of aluminum chlorid sludge remaining insuspension in the decanted liquid by heating to a temperature in thegeneral neighborhood of 450 F. with a small amount of clay and withabout 0.6 pounds of lime per acid number per barrel and filtering toremove products of decomposition, to secure a pure oil of the characterdescribed.

EUGENE AYRES. HERSCHEL G. SMITH.

common: or common.

Patent No. 2,019,037. October 29,1935.

' wanna nus, ET no It is hereby certified thnt error eppeers in theprinted specitieltioa of the lbovenumbered patent requiring correctionas follows: In the drewinzs, Sheet'2, Fig. 2, as shown below shouldnppenr as I part of the Letters Patent:

Oct. 29, 1935. AYRES 5 AL 2,019,037

MANUFACTURE OF IMPROVED HYDROCARBON PRODUCTS Filed March 10, 1952 2Sheets-Sheet 2 SLUDGE fl sglnu) AGITATE I g 2 SETTLE 122511301: nusmznLUBE OIL V CLAY CONTACT FILTER ammo [M3 Eng eize Zyr fiersciegl Q.

and that the said Letters Patent should be read with these correctionstherein the! the same they conform to the record of the one in thePatent Office.

Signed and sealed this 26th day of November, A. D. 1935.

Leslie Frazer Acting Commissioner of Patents.

